fix(vue,explore): index Vue template bindings; rank exact identifiers above plain words

[L0garithmic]

Two fixes found while using codegraph on a large Vue + TypeScript monorepo.

1. Vue templates now produce edges for the identifiers they bind

Vue SFC templates were indexed for component tags only. An identifier a template binds (:prop="x", @event="save", v-if / v-show / v-model values, v-for sources, {{ mustache }} expressions) produced no edge, so "where is myLinkBrandingLocked used" had no answer and explore never rendered the template line that binds a named symbol.

src/extraction/vue-extractor.ts now emits calls for template calls and handler names and references for bare identifiers that the <script> blocks declare or import. It skips v-for and slot locals, object keys, member tails, globals and $-helpers. Explore also renders the same-file use sites of a named symbol, whose source is the whole-file component node that the range builder drops as an envelope.

2. Exact identifiers rank above plain English words

Once a precise query token (camelCase, PascalCase, snake_case, qualified) resolves to a named seed, a file whose only claim is a plain query word (no seed, no precise term, no symbol one edge from a seed) now loses entry-file gate protection and centrality and sorts last, so it only gets leftover budget. Example: WorkspaceMyLinkView appearance section myLinkBrandingLocked spent its budget after the view on an unrelated PHP layout class that matched only "section".

A second commit keeps the files one edge from the named seed (its callers and callees) in the relevance gate, and exempts them from the allocation cliff only while such a word-only file is in the running. Without it, a caller of the exact symbol (the answer to "where is X used") scored under the cliff because it matches no query word, while the word-only file kept its bytes. Its weight and share are unchanged, and when no word-only file exists the cliff behaves exactly as before.

Tests

• __tests__/extraction.test.ts: template bindings produce the expected calls and references edges, and locals, keys, globals and $-helpers produce none.
• __tests__/explore-nl-stopword-collision.test.ts: precise-before-plain ordering.

Rebased onto current main (through #2064). tsc --noEmit is clean, and every __tests__/*explore*.test.ts file plus extraction.test.ts passes (the 692 extraction tests included). One note from running them locally on Windows: with many files per worker a thread died with a V8 "Fatal process out of memory: Zone" before reporting. Each file passes on its own, so this looks like worker memory rather than these changes.